It takes time and effort to draw ellipses according to the elliptic formula. As is well known, a conventional elliptic compass can save much time required for drawing ellipses formularically but it is still troublesome and the precision is very low. Moreover, the ellipses drawn are limited to one specific vector. As a result, the elliptic plate still plays an important role in industrial drawing, though the elliptic plate is limited to a certain size.
In order to eliminate the above mentioned disadvantages of conventional elliptic devices, this invention employs a small motor to drive two discs one of which is a pen carrier and the other of which is a puller carrier and to make them turn synchronously. The puller acting as a base circle drawing control, pulls the pen carrier to draw an ellipse. While the elliptic vector is set by adjusting the radius of circumambulation of the pen carrier and the puller carrier, ellipses in dotted line can be drawn with the help of the drawing control unit.
The main object of this invention is to provide an improved ellipsograph which can, in easy operation, draw ellipses in any vectors from real circle to horizontal line without limitation in size as compared with a conventional elliptic compasses.
Another object of this invention is to provide an improved ellipsograph which can, in integral operation, draw precise ellipses without the errors typically made by conventional elliptic compasses.
This invention relates to an improved ellipsograph capable of a drawing a dotted or dashed line, especially one which, employing a small motor to drive two discs for pen and puller carriers to turn synchronously can, with the movement of the pen carrier pulled by the puller, draw ellipses of various vectors as set by adjusting the radius of circumambulation of the pen carrier and the puller carrier, and in dotted or dashed lines as controlled by a drawing control unit.